"Checklist Content YAML" custom fields accepts and stores data in YAML format. It contains "items" array and each entry contains obligatory "text" property (checklist item text) and optional "checked" property (boolean value for state of the checkbox). It might contain also "description" property for multiline description and "status" property if statuses are enabled.
Here is a valid example:
items: - text: '--- Header (title)' checked: false - text: 'Item #1' checked: true - text: 'Item #2' checked: false - text: 'Item #3' checked: false